Oven



Dec. 1, 1925. 1,564,082

LYON OVEN Filed March 5, 1924 5 Sheets-Sheet 1 INVENTOR Dec. 1, 1925 H. LYON OVEN Filed March 5, 1924 INVENTOR 5 Sheets-Sheet 2 Dec. 1 1925- H. LYON OVEN 5 Sheets-Sheet Filed March TUE/Tr HERE mvzu-roa H. LYON OVEN Filed March 5, 92

- W Iii. F W 0 j 1 1! w 8 5 4 4 H is k INVENTOR Dec. 1,

H. LYON OVEN Filed March 5, 1924 5 Sheets-Sheet 5 INVENTOR Patented Dec. 1, 1925.

UNITED STATES PATENTOFFICE.

HOWARD LYON, OF GLOUCESTER, NEW JERSEY, AflSIGNGR TO WELSBACH COMPANY,

OF GLOUCESTER, NEW JERSEY, A CCFJIORATION 015 NEW JERSEY.

OVEN.

Application filed March 5, 1924. Serial No. 696,995.

To all whom it may concern:

Be it known that I, HOWARD LYON, a citizen of the United States, residing at Gloucester, county of Camden, and State of New Jersey, have invented a new and useful Improvement in Ovens, of which the following is a full, clear, and exact description.

The present invention relates broadly to ovens, and more particularly to gas fired ovens adapted for domestic use, the broad object of the invention being to improve the efficiency of ovens of this type.

It has heretofore been proposed in the art to which this invention relates to utilize both yellow flames and Bunsen or atmospheric flames for general heating purposes. lVhile it is recognized that for a given length of burner more volume of gas can be effectively utilized by a yellow flame burner than by an atmospheric burner, considerable difliculty has been encountered in the use of yellow flames in oven work, for the reason that the flame has tended to lick the walls confining the same, thereby resulting in carbon deposit and a smoky flame. Recourse has, therefore, been had to atmospheric hunters in which the flame direction has been more easily controlled. This, however, has necessitated a larger burner area than would be required with a yellow flame burner in order to raise the temperature of a given oven a given number of degrees in a definite peroidof time. Dun ing ordinary use, it is quite common practice in different forms of domestic ovens to vary the amount of gas consumed within the range of from two feet per hour to fifty feet per hour. lVith the minimum gas consumption, it has been found that the flame produced by an atmospheric burner easily floats off or extinguishes itself, and that ordinary jars such as occasioned by closing and opening the oven door will accomplish the same result, thereby permitting the oven to fill with gas which is not only dangerous, but which spoils articles being cooked. Furthermore, water vapor produced in the oven will frequently quench such a low flame, thereby making its operation unreliable. It has also been found that as the gas supply varles, it is necessary to make corresponding achustments in the the present invention these objectionable features are eliminated by the provision of an oven having a self-contained or oven-contained stack for the products of combustion, which is of greater height than the height of'said chamber, and a portion.

at least of which is of less cross-sectional area than the cross-sectional area of the oven chamber. Preferably, the stack portion of less cross-sectional area than the crosssectional area of the oven is a. prestack or starting stack adapted to more quickly establish the desired circulation of the body of gases within the oven. This starting stack is adapted to receive a burner, preferably of the yellow flame type having a length substantially CO-QXtGIlSlVB with one dimension of the oven. This starting stack of relatively small cross-sectional area is made possible only by the use of a yellow flame burner, which enables the use of a much shorter total length of burner for an oven of given size than where an atmospheric burner is employed. The starting stack, in turn, is largely responsible for the ability to successfully employ a yellow flame burner-without the attendant disadvantages above pointed out.

in order to permit the desired flame conditions to establish themselves quickly, to prevent wavering or licking flames, the invention also contemplates the provision of means cooperating with the starting stack to facilitate lighting, and to render this opera tion safe, and to minimize back pressure on the burner.

The use of a yellow flame burner makes it possible to employ any kind of gas, such as natural gas, coke oven gas, water gas, or the like, since a yellow flame may be offectively used within the limits of gas consumption set forth above without danger of extinguishment, and the stack construction is such as to obviate likelihood of a smoky flame.

Another feature of the invention is the provision of an oven having an oven chambeing so related that it is impossible to turn off the pilot as long as the supply of gas to the main burner is open. This insures an effective pilot flame at all times when the supply of gas to the main burner is on, whereby even in the event of temporary extinguishment of the main burner, relighting thereof is insured. The burners also preferably operate with a minimum air supply, whereby irrespective of the burner setting, the supply of air is not sufficient to carry away a large number of heat units. This enables a given temperature condition ,to be maintained witha minii'num gas consumption.

The present invention also has for one of its objects the provision of means tending to neutralize or minimize the effects of a sudden increased pressure within the oven and counter-flow of the products of combustion, such as usually established by suddenly closing the oven door.

Still another feature of the invention is the provision, in a combination as set foith, of a thermostat to control the fuel supply to the main burner.

The invention also comprehends the relative arrangement of a burner or burners and a stack or stacks such that the products of combustion from the burner must sweep across the entire width of the bottom wall of the oven chamber, thereby uniformly heating the bottom of the oven, and eliminating the objectionable hot and cold spots often present in domestic ovens.

In the accompanying drawings there is shown, for purposes of illustration only, one embodiment of the present invention, it being understood that the drawingsdo not define the limits of the invention, as changes may be made in the construction and operatien therein disclosed without departing from the spirit of the invention or scope of my broader claims.

In the drawings Figure 1 is a front view of a stove em-- bodying my invention;

Figure 2 is a vertical sectional view of the oven, the view being taken at right angles to the plane of Figure 1;

Figure a horizontal sectional View of the oven taken on the line IIIIII of Figure 2,

formed by the walls of a burner box Figure 4 is a vertical sectional View, partly broken away, on the line IV-IV of Figure 2, looking in the direction of the arrows;

Figure 5 is a detail sectional view on an enlarged scale on the line VV of Figure 2;

Figure 6 is a front elevation of the structure illustrated in Figure 5;

Figure 7 is a view similar to Figure 5, illustrating the complete burner and the means for centering the same;

Figure 8 is a detail sectional view on the line VIII-VIII of Figure 5, illustrating a portion of the burner mounting;

I Figure 9 is a detailsectional view on the line IX-IX of Figure 8;

Figure 10 is a detail sectional view on the line of Figure 8; and

.Figure 11 is a sectional view on the line XIXI of'Figure 3.

' Referring to the drawings, there is shown a-stove comprising the usual hot plate A and oven B. The oven comprises spaced inner and outer metal walls 2 and 3, the space between said walls being filled with a suitable insulating material 4. The oven is provided at the front thereof with the usual hinged door C, also comprising inner and outer walls 2 and 3 with insulating material 4 in the space between said walls.

' The oven chamber D is defined by the inner side walls 2 of the oven, the bottom wall 5, which is spaced above the inner bottom wall 2, and the upper wall 6, which spaced from the inner-upper wall 2. This oven chamber is provided with the usual rack guides 7 and is closed by the door O, which. preferably has a channel in the edge portionthereof in which is carried a gasket 0 of heat insulating material adapted to form a seal between the door and face of the oven when the door is closed.

Communicating with the forward end of the space 8 between the bottom wall of the oven chamber D and the inner bottom wall 2 of the oven, is a vertical combustion chamber or starting stack 9-, which extends downwardly from said space andac'ros's sub stantially one entire dimension of the oven chamber, it being herein shown as extending across-substantially the entire front of the oven. The walls of the starting stack are r Spaced from one of the side walls of the burner box 10 is a portion of the insulated oven casing having the filling a of insulating materiahthe bottom of said box also being covered with insulating material. It will be seen, therefore, hat the oven chamber D and the starting stack are substantially completely encased in heat insulating material, there by preventing any material heat losses by radiation.

Arranged in the burner box 10 adjacent the bottom and extending longitudinally of said box and parallel tothe bottom thereof, is a main burner tube 11. lVith the burner in operation, the products of combustion from this burner pass vertically through the burner box, then through the horizontal space 8, and then vertically through the space 12 between the bottom wall 5 of the oven chamber D and the. inner rear wall 2 of the oven. The products of combustion rising through the vertical space 12 pass'into the oven chamber D, as indicated by the arrows in Figure 2. The upper wall 6 of the chamber D is provided with a row of perforations 13 preferably arranged toward the front of the oven and extending transversely thereof. The proclucts of combustion pass fromv the chamber D through the perforations 13 into the space 14 and through said space into the flue 15 at the rear of the oven.

' Adjacent the front of the oven the bottom wall 5 is cut away to form an opening 16, one edge of which is bent downwardly and upwardly, as indicated at 17, to form a support for a door 18 having projecting trunnions 19 journaled in suitable bearings in the bottom wall. Projecting from one end of the door 18 is a. finger 20 which is adapted to overlie a slide 21 loosely mounted in a groove 22 in the bottom wall 5. This slide has a cam portion 23 adapted to gradually lift the finger 20 and thereby the door 18 as the slide is pulled forwardly. This operation may easily be performed when the oven door is open, by merely grasping the upstanding portion 2 1 of the slide and pulling it forwardly. This operation swings the door about its trunnions, whereby it occupies a position upwardly and inwardly inclined toward the rear of the oven. If the gas is turned on. a latch or lighter may be applied to the space thus formed between the door and the bottom wall 5, to light the issuing from the burner. Due to the direction of inclination of the door, any

slight puff. caused by the lighting will be,

directed rearwardly, thus preventing any injury to the person using the oven.

Not only does the door 18 provide an expeditious method of lighting the oven, but it relieves back pressure on the burner, thereby enabling the flames to more quickly assume a normal condition. This is true for the reason that it is unnecessary for the products of combustion to displace all of the gases within the horizontally extending passage 8 in order to establish a draft. The products of combustion may pass directly through the opening into the oven. Thereafter the door may be closed by pushing the slide 21-inwardly, or by simply closing the oven door which in its closing movement engages the end of the slide and accomplishes the same result. During this operation the door 18 closes by gravity. Thereafter the products of combustion are caused to pass through the burner box, thence through the entire horizontal space 8, thus. sweeping the entire bottom of the oven, and thence through the vertical space 12 into the oven. This sweeping of the oven bottom throughout substantially its entire area produces the uniform temperature conditions whereby hot and col-d spots such as frequently found in ovens are entirely obviated. The gases then pass into the oven providing a maximum absorptive area whereby a maximum amount of heat is imparted to any articles within the oven before the gases escape through the openings 13 and space 14 to the flue 15. During both the lighting and the operation of the oven, the burner box serves as a pre-stack, tending to more quickly establish the desired flame conditions. The comparatively small cross-sectional area of this pre-stack and of the space 8 insures a rapid movement of the gases across the oven bottom which not only tends to increase the heat transfer, but to displace any adhering gas globules, thereby mgking an efficient heat interchange possi le.

The burner 11 is preferably of the yellow flame type having a plurality of perforations 25 preferably arranged in two rows, as clearly shown in Figures 5 and 7, with the openings in one row staggered with respect to those in the other row. These openings may be arranged with any desired angle of divergence therebetween deemed desirable for the most efficient flame conditions. The burner in its operative position is preferably located in the horizontally extending passage 26 of the burner box immediately below inwardly projecting ribs 27 on the walls thereof. These ribs provide a comparatively restricted opening 28 through which the flames must pass. This construction has been found highly desirable for insuring the proper supply of air to the flames. This air, in regulated amounts is supplied through a downwardly and inwardly extending passageway 29 in a cover plate 30, the inwardly extending portion of the passage being controlled by a valve 31, as hereinafter more fully described. It will be apparent that this air is brought into intimate relationship with the flames between the ribs 27, thereby thoroughly mixing the air and the fuel'and insuring complete combustion with a minimum of air. Within the burner box the flames are protected from side drafts such as would tend to deflect the same by the walls of the burner box. Adjacent one end of the burner tube 11 is a pilot 32 preferably of the cup type whereby the walls 33 of the cup protect the pilot flame. This pilot flame also preferably comprises diverging: openings" 34 whereby lighting of any gas issuing from the orifices 25 of the main burner is insured.

The entire burner structure is preferably of such nature that it may be easily swung outwardly into the dotted line position shown in Figure 5 to permit inspection or cleaning thereof. In order to accomplish this operation, the front plate 30 is removed by loosening the holding screws 35, thereby giving access to the lower portion-of the burner box. The burner tube 11 is preferably secured in the inner end of a manifold casing 36 the outer portion of which projects downwardly in the form of a ground cock 37 swiveled in a fixed casting 38. The casting 38 has a passage 39 for the gas supply to the main burner, and a second passage 40 for the gas supply to the pilot. The passage 89 communicates with a pcripherally extending groove 41. in the cock 37, which groove communicates with a central passage 42 by means of transverse openings 43. The manifold 36 is hollow through out its entire length andthe flow of gas from the passage 42 therethrough and into the burner is controlled by a regulating screw 44.

The passage 40 communicates with a similar groove 45 in the cock 37, this groove communicating through a passage 46with the pilot. as clearly shown in Figure 8. By reason of this construction it will be apparent that irrespective of the relative position between the manifold and the casting, the flow of gas to the burner and the pilot will not be interrupted. The manifold 36 has projecting therefrom afinger 47 by means of which the {burner may be easily swung to its dotted line position when the plate 30 has been removed. The flow of gas to the pilot through the passage 40 may be controlled at will by a suitable regulat ing screw 48.

The stove is provided with the usual iurner manifold 49 extending in front of the hot plate A for supplying gas thereto. This burner manifold adjacent its inner end is tapped to receive a main gas cock 5O having a controlling handle 51. This cock controls the flow of gas from the burner manifold to the pipe 52, communicating with a vertically extending pipe 53 leading to the valve casing 54 of the thermostat 55. This thermostat. as clearly shown in F ure 2. is located so as to be directly acted upon by thehot gases cscapingfrom the oven through the opening 13. Ittherefore operates directly in accordance with the temperature of these gases to control the flow of gas through the casing 54 to :a second pipe 56 leading downwardly and communi eating with a horizontally extending pipe 56 'threaded into the fixed casting 3 8. In this manner the flow of gas is controlled manually by the cock 50 and automatically, irrespective of this manual setting, by the thermostat 55.

Adjacent the cock 50 is a second cock 57 controlling the flow of gas from the burner manifold to the tube 57 communicating with the passage 40 in the casting 38. It is desirable to provide an im'er-control' between the cocks 50 and 57 whereby opening of the cook 50 will insure opening of the cock 57 and closing of the cook 57 will be prevented as long as the cock 50 is open. This result is accomplished by providing a lever 58 which normally occupies the position indicated in dotted lines in Figure 5. When the control handle 51 is swung from its full linev position of Figure 1 to its full line position of Figure 5. this lever isswung from its dottedlineposition of Figure 5 to its full line position. During. this move ment it engages a similar lever 59 project ing from the cock 57 and moves it from its dotted line position of this figure to its full line position. With the parts in the position shown in full lines in Figure 5, the cocks are both open so that the flow of gas from the burner manifold to the main burner and to the pilot is permitted. As long as the main cook 50 is in open position it is impossible to close the cook 57 due to the engagement of the lever 59 with the lever 58. It will be apparent, however, that as soon as the gas supply to the main burner 1s turned off, the lever 58 moves out of con tact with the lever 59 thereby making it 100 possible. to close the pilot control cock at will. This construction is of advantage for the reason that it insures a supply of gas to the pilot at all times during which there is any possibility of a gas flow to the main 105 burner. In this manner the lighting of any gas issuing from the main burner orifices is insured.

The operation of the main gas cock 50 is also preferably relied upon to control the ex 110 tent of opening of the air valve 31, whereby the amount of air admitted to the main burnor is to a large extent controlled by the position, or the amount of opening, of the cook 50. This maybe accomplished by securing 115 to the pipe 52 a bracket 60 having pivotally secured thereto an arm 61 bent upwardly at its forward end and bifurcated, as clearly shown in Figures 2 and 6. Secured at some intermediate point to the arm 61 is a slide 120 62 extending laterally through the oven wall into the lower portion .26 of the burner box. This slide has its portion within the burner box preferably shaped as indicated in Figure 6 to provide an inclined portion 63 125 and a depression 64. lVith the cook 50 in its closed position, the slide 62 isin its extreme, left hand position asviewed in Figures 5, 6 and 7 At this time the depression 64 underlies a finger 65 projecting rearwardlyfrom the valve 31, thereby permitting the valve to move to its closed position to cut off the passage of air into the burner-box. As the cook 50 is opened, the arm 61 and the slide 62 are moved to the right as viewed in these figures, thereby causing the inclined portion 63 to engage and lift the finger 65 to move the valve into the position illustrated in Figure 2. With this construction, the main supply of air is cut oflf with the cutting olf of gas flow to the main burner by the cook 50, thereby keeping the supply of air at a minimum. This is of decided advantage when given temperature conditions are being maintained within the oven entirely by the use of the pilot flame as the supply of air i not suflicient to carry off any large amount of heat.

In actual practice I have found that the sudden closing of the oven door creates a temporary increase of pressure within the oven, which tends to dissipate itself by establishing a flow in opposition to the normal flow of the products of combustion from the burner box. This action has heretofore been extremely objectionable, as it has frequently resulted in the complete extinguishment of the burner. In the present construction I not only minimize the effect of such an increased pressure within the oven, but actually take advantage of the conditions thus temporarily created to assist in the maintaining of the desired draft conditions. This may be accomplished by utilizing the space between the front wall of the burner box and the enclosing casing as an equalizing passage 66 communicating at its upper end with the interior of the oven adjacent the door, as clearly shown in Figures 8 and 11, and at its lower end comn'nuiicating with the starting stack through a suitable opening or openings 67. By reason of the pro vision of this passage it will be obvious that upon closing the oven door there is created a flow downwardly through the equalizing passage and out through the opening or openings 67 into the burner box above the point of air supply. As this flow may be composedlargely of products of combustion,

it; is desirable that the opening or openings 67 be located as set forth so that the supply of air to the flames is not contaminated. This flow from the equalizing passage tends to increase the draft effect within the start-- ing stack, thereby not only tending to produce an upward draft therein, but also'tending to counteract the effect of any counterflow set up through the vertical space 12 and the horizontal space 8. In this manner it is made substantially impossible to extinguish either the main burner or the pilot, irrespective of how hard the oven door is closed.

In lighting the oven, it is desirable to move the thermostatic valve. to its full open position-to permit amaximum flow of gas to the burner in order toinsure quick lighting. Thereafter the thermostatic valve may be set for any desired temperature, after space under the oven chamber from cooled or useless gases. This makes possible to a large extent the use of a yellow flame burner since the increased draft produced thereby obviates danger of a smoky flame.

Another advantage of the invention arises from the provision of 'an-oven chamber and a combustion chamber substantially completely encased in insulating material adapted to reduce heat losses by radiation to a minimum and to provide a certain amount of heat storage when the oven is not in use. This enables the pilot burner to be kept continuously lighted and the heat therefrom stored during periods of disuse of the oven,

whereby this stored heat will be immediately available when it is desired to use the oven, thereby eliminating the necessity of bringing a cold oven up to temperature such as ordinarily required.

A further advantage of the invention arises from the relative arrangement of the burner and stack such that the products of combustion are caused to sweep across substantially the entirearea of the oven bottom from one side thereof to the other.

Still further advantages arise from the provision of means for neutralizing the detrimental. effects of closing an oven door and from the provision of means preventing turning off of the pilot while gas to the main burner is turned on.

I claim:

1. In an oven, a yellow flame burner under the oven chamber and substantially coextensive with one dimension thereof, and a starting stack for the products of combustion extending upwardly from said burner throughout substantially the full length thereof and of less cross sectional area than the cross sectional area of said chamber, substantially as described. a i

2. In an oven, a yellow flame burner beneath the oven chamber and substantially coextensive with one dimension thereof, and stack means for the products of combustion from said burner, said burner and stack means being relatively arranged so that the products of combustion are caused to initialy sweep in a unlform direction from the point of impact across the entire Width of the bottom of the oven chamber, substantial- 1y as described. a

3.;In an oven, a. yellowflame burner extending substantially parallel to and adjacent one side-of the oven chamber but spaced therefrom ina vertical directiomand a starting stack under the oven chamber and cooperating with said burner, substantially as described.

4. In an oven, a burner extending substantially parallel to and adjacent one side of the oven chamber, and a stack of less cross sectional area than that of the oven chamber enclosing said burner, said stack being located under the oven chamber, substantially as described.

5. In combination, an oven, an elongated yellow flame burner therefor, means below the oven and substantially coextensive with. one dimension thereof enclosing the burner and adapted to confine the heat-from the burner and direct that confined heat together with the products of combustion against the bottom or said oven throughout substantially onedimension of the oven, and means for controlling the supply of air to said means, substantially as described. r

6. In an oven, a yellow flame burner under the oven chamber and substantially coextensive with one dimension thereof, and a'starting stack interposed between the oven chamber and burner adapted to concentrate the heat from said burner and direct said concentrated heat against the bottom wall of said chamber, substantially as described.

7. In combination, an oven chamber, an

elongated burner having. orifices therein, a

bringing the supplied air into intimate contact with the flame issuing from said orifices, substantially as described. I

8. In an oven, 2). burner, a starting stack therefor below the oven chamber, and means for supplying air to said burner and deflecting the air into intimate contact. with the burner flames, substantially as described.

9. In an oven, a burner, and a combustion chamber, the oven chamber and said combustion chamber being substantially completely encased in insulating material and the combustion chamber constitutinga start: ing'stack for the burner located below and under the oven chamber and of materially less cross sectional area than that of. the oven chamber, said combustion chamber extending substantially coextensive with one dimension of the oven chamber, substantial ly as described.

10. In an oven, an oven chamberhaving menace openings therein 'for the passage there. through of products of combustion, a starting stack of less cross sectional area than the oven chamberlocated below said chamber for completing combustion before said openings are reached, and a yellow flame burner located within and protected by said stack, substantially as described.

11.- In an oven, an oven. chamber, a start-. ing stack of less cross sectional area than the oven chamber located below said chamber-,and a yellow flame burner within and protectedby said stack, said stack in one direction extending across substantially one entire dimension of the chamber, substantially as described.

12. In combination, an oven chamber having normal openings to permit the circulation of products of combustion therethrough, a burner, and means minimizing the effect of variations in pressure in the'oven chamber on the burner through such openings, substantially as described.

1? In an oven, a burner supplying products of combustion to the oven, and a plurality of separate passages each communicating with the burner at one end and the oven at the other end and adapted to have opposing flow conditions therethrough when the oven door is closed, substantially as olescribed.

14. In an oven, a burner supplying products of combustion to the oven, said oven having openings to permit the circulation of such products therethrough, and other means causing increased pressure conditions within the oven such as produced by 0108- ingthe oven door to. tend to increase draft effect on the burner, substantially as described.

15. In an oven, a burner-,a passage con-Q veying products of combustion from the burner to the oven, and a second passage between the oven and burner tending to assist the flow of products through said first mentioned passage in the normal direction upon closing the oven door, substantially as described.

16. In an oven, a burner, a passage conveying products of combustion from the burner to; the oven, and a second passage intersecting said first mentioned passage above the burner and tending to assist the flow of products through said first mentioned pas? sage. in the normal. direction upon closing the oven door, substantially as described.

17. In an oven, a burner, aburner box therefor of less cross sectional area than the area of the oven chamber, and a door adapted to be opened for lighting the oven to relieve back pressure on the burner, said burner box. being so-located as. to direct products. of combustion directly toward Said door, substantially as described.

-l8. In an oven.'a burner, a burner box;

therefor of less cross sectional area than the area of the oven chamber and a door adapted to be opened for lighting the oven to relieve back pressure on the burner, said burner box being so located as to direct products of combustion directly toward said door and said door being arranged to direct the flame into the oven when the burner is lighted, substantially as described.

19. In an oven burner having an air inlet, means for restricting the air supply through said inlet, and air diverting means on opposite sides of the burner for confining the restricted air and flame and directing and deflecting the restricted air into intimate relationship with the flame from opposite sides of the flame to thereby control the flame direction by the opposing air streams,

substantially as described.

20. In an oven, an elongated yellow flame main burner, means for supplying air to said burner and directing the same at an angle to and into the path of travel of the flame, a valve for controlling the supply of fuel to said burner, and means operatively connected to said valve for regulating the supply of air in accordance with the posi tion of said valve, substantially as described.

21. In an oven, a burner supplying products of combustion to the oven, there being an air supply for said burner, and a plurality of separate passages, each communicating with the burner at one end and with diflerent parts of the oven at the other end and adapted to have opposing flow condi tions therethrough when the oven 'door is closed, one of said passages communicating with the burner above the point of air supply therefor, substantially as described.

22. In an oven burner, having an air inlet, means for restricting the air supply through said inlet for thereby controlling the air to the burner, means for directing all of the air from said supply toward the. burner flame angularly from opposite sides of the burner flame, and a combustion chamber enclosing the burner flame and confining and directing the heat therefrom throughout substantially one entire dimension of the oven, substantially described.

23. In combination, an oven, an elongated yellow flame burner for heating said oven, means for restricting the air supplied to said burner, means for directing all of the restricted air from said-supply toward the burner flame angularly from opposite sides of the burner flame, and a combustion chamber enclosing the burner flame and confining and directing the heat therefrom throughout substantially oneentire dimension of the oven, substantially asdescribed.

24. In an oven, a burner extending substantially parallel to and adjacent one side of the oven chamber, and a stack of less cross sectional area than that ofthe oven chamber enclosing said burner, said stack being located under the oven chamber, there being insulating means for said oven and said stack, substantially as described.

25. In an oven, a yellow flame burner extending substantially parallel to and adjacent one side of the oven chamber, and a stack of less cross sectional area than that of the oven chamber enclosing said burner, said stack being located under the oven chamber,there being insulating means for said oven and said stack, substantially as described.

In testimony whereof I have hereunto set my hand.

HOWARD LYON. 

